Improvement in making pivot-holes in keys of musical instruments



SALMON H. WlLDER.

Improvement in Making Pivot Holes in Keys of Musical Instruments.

No. 125,239. PatentedAprH2J872.

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SALMON H. WILDER, OF DEEP RIVER, CONNECTICUT, ASSIGNOR TO WILLIAM A. REED, OF SAME PLACE.

IMPROVEMENT IN MAKING PlVOT-HOLES lN KEYS 0F MUSICAL INSTRUMENTS.

Specification forming part of Letters Patent No. 125,239, dated April 2, 1872.

SPECIFICATION.

To all whom it may concern:

Be it known that I, SALMONH. WILDER, of Deep River, in the county of Middlesex and State of Connecticut, have invented certain new and useful Improvements in Making the Pivot-Holes in Keys for Musical Instruments; and I do hereby declare that the following is a full, clear, and exact description thereof, whereby a person skilled in the art can make and use the same, reference being had to the accompanying drawing and to the letters of reference marked thereon.

Like letters in the figures indicate the same parts.

ln piano-fortes, organs, melodeons, or other keyed instruments, the impulse is communicated from the key-board to the action by means of bars or levers that rest upon a horizontal bar as a fulcrum, and to which they are attached by means of upright pins passing through holes in the levers. These holes are made to nearly or quite fit the pins at the bottom, but are enlarged at the top to permit a free vibration of the lever. The object of my invention is to provide a cheaper, better, and more expeditious method of forming these holes. Heretofore the usual methodsof makin g them have been either to bore a small hole the size of the pin through the lever and then cut out an elongated slot by hand for the upper end of the pin to move in or to bore a large hole nearly through the lever and a small one the rest of the way at the bottom to fit the pin. The first of these-is laborious and expensive, and the second cuts away too much of the lever-bar, as the round hole has to be of a diameter equal to the full play of the pin in the lever. This leaves only a very thin shell at the sides. My invention consists in a method of making a hole or slot of the proper size and shape without the disadvantages of the usual methods.

In the accompanying drawing, Fig. 1 shows a longitudinal vertical section through the middle of a key-lever with. the hole as made by my improved method. Fig. 2 shows a top view of the lever. Fig. 3 is a front view of the tool for forming the rectangular or top part of the hole. Fig. 4 is a side view of the same.

To form the hole. in my improved method, I first bore through the bar a hole, a, of the proper size for the pin, followed by a larger hole, b, nearly through the bar, of the width of the rectangular slot. These holes are made at oneoperation with a double bit in the usual manner of boring such holes. I then introduce the rectangular wedge-shaped tool 0, Figs. 3 and 4, into the top of the hole and drive it down by pressure or otherwise until the edge comes nearly down to the smaller part of the hole at the bottom of the bar. The inclined sides of the tool push back the fibers ot' the end grain of the wood, and, when the tool is withdrawn, a clean, sharp'cornered and smooth opening is left of the exact size and shape required. The tool is inserted in a press operated by the foot or otherwise, and is made to descend to an exact gauge when the lever-bar is placed beneath it, so that all the rectangular openings made by it are of an exact and uniform size. The tool can be also operated by hand, if desired, and driven to the p roper depth. In order to exactly determine" he position of the tool 0 relative to the bar and cause it to enter the hole bin the proper place, independent of the width or thickness of the lever-bar, which may be to a small extent variable, a small pin, d, is fixed in the platform upon which the bar rests when the tool is pressed into it. This enters the hole a and insures the tool being exactly over the hole b in all cases, so as to enter it squarely and uniformly and form a regular and smooth aperture.

Claims.

\Vhat I claim as my invention is-- 1. The method of forming the hole in the lever-bar herein set forth.

2. The wedgeshaped tool for forming the rectangular part of a hole in the lever-bar, with inclined sides for crushing the end-grain of the Wood, substantially as herein described.

3. The combination of the tool 0 and the pin d, substantially as and for the purpose herein specified.

SALMON H. WILDER.

Witnesses:

Tnno. G. ELLIs, BEN. O. (300KB. 

